1. Field of the Invention
The present invention relates generally to an optical memory for storing information together with a method and apparatus for recording such information. More specifically, the present invention relates to an optical memory for storing human readable pictorial information and machine readable digital information within the same format as well as a laser beam recording method and apparatus for recording such information in an easily accessible manner.
2. Description of the Prior Art
State-of-the-art laser recording systems have demonstrated the capability of recording large blocks of information at high recording rates. This information may be recorded in either a machine readable digital format or, alternatively, in a human readable pictorial format. In the former, digitized imagery is stored in bit sequential fashion by appropriate encoding techniques such that it may later be retrieved to reconstruct, for example, an original scene; while, by the latter method, a visual analog presentation of the scene is provided.
The recording and storage of optical data in the digital domain provides the advantage of allowing very high bit packing densities, however, the stored information remains in the digital domain and as such is less accessible than pictorial data. The recording of optical data in human readable form, on the other hand, provides a convenient visual representation of the original scene, however, it does so at a loss of digital data dynamic range storage due to the inability of conventional continuous-tone recording mediums to contain the dynamic range normally encountered in advanced sensors.
Thus, in the prior art, the practice has become to record and store large dynamic range pixels in the pure digital domain while providing a separate image recorder to reconstruct the pictorial format. This is obviously a less than satisfactory situation and it would be desirable to provide an optical recording technique which will permit the recording of large digital pixel words within a human readable pictorial format, but organized for machine retrieval of the original digital information.